At any given moment the earth's atmosphere contains 326 million cubic miles of water and of this, 97% is saltwater and only 3% is fresh water. Of the 3% that is fresh water, 70% is frozen in Antarctica and of the remaining 30% only 0.7% is found in liquid form. Atmospheric air contains 0.16% of this 0.7% or 4,000 cubic miles of water which is 8 times the amount of water found in all the rivers of the world. Of the remaining 0.7%, 0.16% is found in the atmosphere; 0.8% is found in soil moisture; 1.4% is found in lakes; and 97.5% is found in groundwater.
Nature maintains this ratio by accelerating or retarding the rates of evaporation and condensation, irrespective of the activities of man. Such evaporation and condensation is the means of regenerating wholesome water for all forms of life on earth.
In addition, many of the world's fresh water sources are contaminated. A total of 1.2 billion people in the world lack access to safe drinking water and 2.9 billion people do not have access to proper sanitation systems (World Health Organization). As a result, about 3.4 million people, mostly children, die each year from water-related illnesses. According to the United Nations, 31 countries in the world are currently facing water stress and over one billion people lack access to clean water. Half of humanity lacks basic sanitation services and water-borne pathogens kill 25 million people every year. Every 8 seconds, a child dies from drinking contaminated water. Furthermore, unless dramatic changes occur, soon, close to two-thirds of the world's population will be living with freshwater shortages.
There is a global need for cost effective and scalable sources of potable water. Current technologies require too much energy to operate efficiently and the resultant cost of the treated water puts these technologies out-of-reach for the majority in need. Desalination plants exist in rich nations such as the United States and Saudi Arabia but are not feasible everywhere. The lack of infrastructure in developing nations makes large plants with high-volume production impractical, as there is no way to transport the water efficiently.
There is a need for small scalable water extraction devices that meet the needs of individuals, communities and industries. This invention responds to that need by providing an extraction unit that functions “off-the-grid” to make clean pure water, anywhere where the need exists.
The present invention is a device that extracts moisture vapour from atmospheric air for use as a fresh water source. The device may utilize the sun as the primary energy source thereby eliminating the need for costly fuels, hydro or battery power sources. The water collection device of the present invention provides flexibility over prior devices, allowing for productive installations in most regions of the world. As the water collection device's preferred power source is solar energy, the amount of available power for the device increases as installations of the device are closer to the equator where there is more sunlight year round.
The invention is designed to allow one small water cooler sized unit to provide cooking and drinking water for a family, simply by harvesting the water vapour from humid air. Private individuals, industries and communities could control their own water supply through the use of the device's technology. It is also practical for many uses in domestic, commercial or military applications and offers ease of use and clean water of a highest quality anywhere, anytime. The modular design of these devices allow for increased capacity, simply by adding more modules.
In addition to domestic use, larger units based upon the same basic technology are appropriate for other applications in which larger water supplies are required. For example, a 12 Volt compressor in the cooling system within the device, may be replaced with a larger 110 Volt compressor with the appropriately sized other components such as the evaporator and the condenser, and the unit will be capable of condensing larger quantities of water as electrical power is more readily available.
The device's solar water powered condenser technology may be applied to a variety of uses from residential to recreational and from commercial and agricultural to military and life saving in extreme water deprived regions of the world.
This invention may be used for obtaining pure drinking water, for cooking purposes or for other household uses such as cleaning or bathing. The system may also be used on boats or in vacation areas, on camping trips, trekking, and places where drinking water delivery systems are not developed. The unit may be used to produce fresh water for bottling purposes or for large commercial applications such as restaurants, offices, schools, hotel lobbies, cruise ships, hospitals and other public buildings. The system may also be used in playing fields and sports arenas.
Additionally, the device may be used to augment the supply of water used to irrigate selected crops using micro or drip irrigation systems. These systems deliver the right amount of water at the right time, directly to the roots of plants. As well, the technology may be used to for bottled water production or virtually any other application where water is needed.
The proposed technology provides an opportunity to end much suffering. The death and misery that flow from unsafe water is overwhelming. More than 5,000 children die daily from diseases caused by consuming water and food contaminated with bacteria, according to a recent study released by UNICEF, the World Health Organization (WHO) and the UN Environment Program (UNEP).
Currently, 1.2 billion people have no access to safe drinking water and that number is increasing steadily, with forecasts of a potential 2.3 billion (or one-third of the earth's population) without access to safe water by 2025 (World Health Organization's statistics from World Commission on Water for the 21st Century). These at-risk children and their families are not restricted to rural areas in undeveloped nations. “Millions of poor urban dwellers have been left without water supply and sanitation in the rapidly growing cities of the developing world. The poor are often forced to pay exorbitant prices for untreated water, much of it deadly,” reports William Cosgrove, director of World Water Vision, Paris. The device, according to the invention, can relieve much of this suffering.
A rapid increase in water demand, particularly for industrial and household use, is being driven by population growth and socioeconomic development. If this growth trend continues, consumption of water by the industrial sector will be double by 2025 (WMO). Urban population growth will increase the demand for household water, but poorly planned water and sanitation services will lead to a breakdown in services for hundreds of millions of people. Many households will remain unconnected to piped water.
The present invention offers a practical and affordable solution to many of the world's water supply problems.
It should be noted that while much of the prior art is based on simply extracting what can be extracted from the air using a simplistic and uncontrolled process, some water will be extracted, but with little concern for efficiency. This lack of efficiency can be explained by understanding the different types of heat that are used in the process of extracting water from air.
The heat that is used to bring air temperature down to the dew point is “specific heat”. The heat used to bring the temperature of air below the dew point is “latent heat” and represents a dynamic variable in the condensation process. The optimal condensation process uses as little “latent heat” as is possible.
The dew point of air is the temperature at which the water vapour in the air becomes saturated and condensation begins.
For reference, specific heat means the amount of heat, measured in calories, required to raise the temperature of one gram of a substance by one Celsius degree.
Latent heat means: The quantity of beat absorbed or released by a substance undergoing a change of state, such as ice changing to water or water to steam, at constant temperature and pressure. This is also called heat of transformation.
In the optimal condensation process if too much air is drawn through the system, the system cannot transfer enough of the total volume of air to a temperature below the dew point, therefore resulting in poor performance from the system.
If not enough air is drawn through the device the air temperature will drop below the dew point but as there is less air moving through the system, there is respectively less water available to be drawn from that air. As well, other issues that arise when too little air is moved through the system such as freezing and wasted energy in the overuse of “latent” beat. Therefore there is an optimal quantity of air that travels through the system based upon a number of variables and that optimal quantity of air will change as the other variables change. It is therefore necessary to have a system that is monitored and reacts to the changes in temperature and humidity so as to ensure ongoing optimal operation.